This project is aimed at understanding the biochemical processes by which human leukocytes export the biologically potent lipid mediator, leukotriene (LT) C4. LTC4 is a potent bronchoconstrictor, and has been suggested to be a major contributor to airway constriction. The LTC4 transporter regulates the release of LTC4 and hence potentially regulates the local concentration of this mediator.Plans are to study the biochemical and biophysical properties and the structure function relationship of this protein. To achieve these goals, the investigator proposes to isolate and clone the LTC4 transport protein. A number of specific aims are proposed to achieve this goal and to further investigate the role of LTC4 in the pathogenesis of attenuated pulmonary function.